Design, 3D printing, and fatigue analysis of bone implant lattices: a study on structural integrity and failure mechanisms

Abstract This investigation examined the mechanical strength and failure behaviour of various 3D printed lattices for implantation in bones, consisting of octahedral, double pyramid, diamond and cubic lattices. The combination of this research methodology includes a finite element analysis and fatigue testing. Low-cycle compressive fatigue tests were performed using specialized equipment, in addition to the employment of a scanning electron microscope for the properties of the surface and failure modes. The results of this study show that the octahedral lattice provides improved structural performance, a small amount of deformation, uniform stress distribution, and the greatest levels of fatigue resistance. Both diamond and double pyramid lattices indicate moderate deformation and fatigue strength; therefore, they are recommended where flexibility, together with high performance, is a concern. However, the cubic lattice was the worst case, resulting in the highest localized stress and poor ductility. Based on this extensive comparison of identifiers when using fused lattices configured for PLA materials, further studies must introduce physiological stimuli and use versatile biomaterials such as PEEK and titanium. The findings around lattice structure re-emphasize the criticality of lattice choice in the overall improvement of implant outcomes, with the octahedral lattice identified to have impressive fatigue properties that will work well in weight-bearing implants. This study furthers the field of biomedical implant science which could help improve the prognosis of patients through the use of robust bone implants.